ssh-keygen.c

   1 /*
   2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   3  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   4  *                    All rights reserved
   5  * Identity and host key generation and maintenance.
   6  *
   7  * As far as I am concerned, the code I have written for this software
   8  * can be used freely for any purpose.  Any derived versions of this
   9  * software must be clearly marked as such, and if the derived work is
  10  * incompatible with the protocol description in the RFC file, it must be
  11  * called by a name other than "ssh" or "Secure Shell".
  12  */
  13
  14 #include "includes.h"
  15 RCSID("$OpenBSD: ssh-keygen.c,v 1.65 2001/06/24 05:35:33 markus Exp $");
  16
  17 #include <openssl/evp.h>
  18 #include <openssl/pem.h>
  19
  20 #include "xmalloc.h"
  21 #include "key.h"
  22 #include "rsa.h"
  23 #include "authfile.h"
  24 #include "uuencode.h"
  25 #include "buffer.h"
  26 #include "bufaux.h"
  27 #include "pathnames.h"
  28 #include "log.h"
  29 #include "readpass.h"
  30
  31 /* Number of bits in the RSA/DSA key.  This value can be changed on the command line. */
  32 int bits = 1024;
  33
  34 /*
  35  * Flag indicating that we just want to change the passphrase.  This can be
  36  * set on the command line.
  37  */
  38 int change_passphrase = 0;
  39
  40 /*
  41  * Flag indicating that we just want to change the comment.  This can be set
  42  * on the command line.
  43  */
  44 int change_comment = 0;
  45
  46 int quiet = 0;
  47
  48 /* Flag indicating that we just want to see the key fingerprint */
  49 int print_fingerprint = 0;
  50 int print_bubblebabble = 0;
  51
  52 /* The identity file name, given on the command line or entered by the user. */
  53 char identity_file[1024];
  54 int have_identity = 0;
  55
  56 /* This is set to the passphrase if given on the command line. */
  57 char *identity_passphrase = NULL;
  58
  59 /* This is set to the new passphrase if given on the command line. */
  60 char *identity_new_passphrase = NULL;
  61
  62 /* This is set to the new comment if given on the command line. */
  63 char *identity_comment = NULL;
  64
  65 /* Dump public key file in format used by real and the original SSH 2 */
  66 int convert_to_ssh2 = 0;
  67 int convert_from_ssh2 = 0;
  68 int print_public = 0;
  69
  70 /* default to RSA for SSH-1 */
  71 char *key_type_name = "rsa1";
  72
  73 /* argv0 */
  74 #ifdef HAVE___PROGNAME
  75 extern char *__progname;
  76 #else
  77 char *__progname;
  78 #endif
  79
  80 char hostname[MAXHOSTNAMELEN];
  81
  82 static void
  83 ask_filename(struct passwd *pw, const char *prompt)
  84 {
  85         char buf[1024];
  86         char *name = NULL;
  87
  88         switch (key_type_from_name(key_type_name)) {
  89         case KEY_RSA1:
  90                 name = _PATH_SSH_CLIENT_IDENTITY;
  91                 break;
  92         case KEY_DSA:
  93                 name = _PATH_SSH_CLIENT_ID_DSA;
  94                 break;
  95         case KEY_RSA:
  96                 name = _PATH_SSH_CLIENT_ID_RSA;
  97                 break;
  98         default:
  99                 fprintf(stderr, "bad key type");
 100                 exit(1);
 101                 break;
 102         }
 103         snprintf(identity_file, sizeof(identity_file), "%s/%s", pw->pw_dir, name);
 104         fprintf(stderr, "%s (%s): ", prompt, identity_file);
 105         fflush(stderr);
 106         if (fgets(buf, sizeof(buf), stdin) == NULL)
 107                 exit(1);
 108         if (strchr(buf, '\n'))
 109                 *strchr(buf, '\n') = 0;
 110         if (strcmp(buf, "") != 0)
 111                 strlcpy(identity_file, buf, sizeof(identity_file));
 112         have_identity = 1;
 113 }
 114
 115 static Key *
 116 load_identity(char *filename)
 117 {
 118         char *pass;
 119         Key *prv;
 120
 121         prv = key_load_private(filename, "", NULL);
 122         if (prv == NULL) {
 123                 if (identity_passphrase)
 124                         pass = xstrdup(identity_passphrase);
 125                 else
 126                         pass = read_passphrase("Enter passphrase: ",
 127                             RP_ALLOW_STDIN);
 128                 prv = key_load_private(filename, pass, NULL);
 129                 memset(pass, 0, strlen(pass));
 130                 xfree(pass);
 131         }
 132         return prv;
 133 }
 134
 135 #define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
 136 #define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
 137 #define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
 138 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 139
 140 static void
 141 do_convert_to_ssh2(struct passwd *pw)
 142 {
 143         Key *k;
 144         int len;
 145         u_char *blob;
 146         struct stat st;
 147
 148         if (!have_identity)
 149                 ask_filename(pw, "Enter file in which the key is");
 150         if (stat(identity_file, &st) < 0) {
 151                 perror(identity_file);
 152                 exit(1);
 153         }
 154         if ((k = key_load_public(identity_file, NULL)) == NULL) {
 155                 if ((k = load_identity(identity_file)) == NULL) {
 156                         fprintf(stderr, "load failed\n");
 157                         exit(1);
 158                 }
 159         }
 160         key_to_blob(k, &blob, &len);
 161         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
 162         fprintf(stdout,
 163             "Comment: \"%d-bit %s, converted from OpenSSH by %s@%s\"\n",
 164             key_size(k), key_type(k),
 165             pw->pw_name, hostname);
 166         dump_base64(stdout, blob, len);
 167         fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
 168         key_free(k);
 169         xfree(blob);
 170         exit(0);
 171 }
 172
 173 static void
 174 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 175 {
 176         int bits = buffer_get_int(b);
 177         int bytes = (bits + 7) / 8;
 178
 179         if (buffer_len(b) < bytes)
 180                 fatal("buffer_get_bignum_bits: input buffer too small: "
 181                     "need %d have %d", bytes, buffer_len(b));
 182         BN_bin2bn((u_char *)buffer_ptr(b), bytes, value);
 183         buffer_consume(b, bytes);
 184 }
 185
 186 static Key *
 187 do_convert_private_ssh2_from_blob(char *blob, int blen)
 188 {
 189         Buffer b;
 190         Key *key = NULL;
 191         char *type, *cipher;
 192         u_char *sig, data[10] = "abcde12345";
 193         int magic, rlen, ktype, i1, i2, i3, i4;
 194         u_int slen;
 195         u_long e;
 196
 197         buffer_init(&b);
 198         buffer_append(&b, blob, blen);
 199
 200         magic  = buffer_get_int(&b);
 201         if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
 202                 error("bad magic 0x%x != 0x%x", magic, SSH_COM_PRIVATE_KEY_MAGIC);
 203                 buffer_free(&b);
 204                 return NULL;
 205         }
 206         i1 = buffer_get_int(&b);
 207         type   = buffer_get_string(&b, NULL);
 208         cipher = buffer_get_string(&b, NULL);
 209         i2 = buffer_get_int(&b);
 210         i3 = buffer_get_int(&b);
 211         i4 = buffer_get_int(&b);
 212         debug("ignore (%d %d %d %d)", i1,i2,i3,i4);
 213         if (strcmp(cipher, "none") != 0) {
 214                 error("unsupported cipher %s", cipher);
 215                 xfree(cipher);
 216                 buffer_free(&b);
 217                 xfree(type);
 218                 return NULL;
 219         }
 220         xfree(cipher);
 221
 222         if (strstr(type, "dsa")) {
 223                 ktype = KEY_DSA;
 224         } else if (strstr(type, "rsa")) {
 225                 ktype = KEY_RSA;
 226         } else {
 227                 xfree(type);
 228                 return NULL;
 229         }
 230         key = key_new_private(ktype);
 231         xfree(type);
 232
 233         switch (key->type) {
 234         case KEY_DSA:
 235                 buffer_get_bignum_bits(&b, key->dsa->p);
 236                 buffer_get_bignum_bits(&b, key->dsa->g);
 237                 buffer_get_bignum_bits(&b, key->dsa->q);
 238                 buffer_get_bignum_bits(&b, key->dsa->pub_key);
 239                 buffer_get_bignum_bits(&b, key->dsa->priv_key);
 240                 break;
 241         case KEY_RSA:
 242                 e  = buffer_get_char(&b);
 243                 debug("e %lx", e);
 244                 if (e < 30) {
 245                         e <<= 8;
 246                         e += buffer_get_char(&b);
 247                         debug("e %lx", e);
 248                         e <<= 8;
 249                         e += buffer_get_char(&b);
 250                         debug("e %lx", e);
 251                 }
 252                 if (!BN_set_word(key->rsa->e, e)) {
 253                         buffer_free(&b);
 254                         key_free(key);
 255                         return NULL;
 256                 }
 257                 buffer_get_bignum_bits(&b, key->rsa->d);
 258                 buffer_get_bignum_bits(&b, key->rsa->n);
 259                 buffer_get_bignum_bits(&b, key->rsa->iqmp);
 260                 buffer_get_bignum_bits(&b, key->rsa->q);
 261                 buffer_get_bignum_bits(&b, key->rsa->p);
 262                 generate_additional_parameters(key->rsa);
 263                 break;
 264         }
 265         rlen = buffer_len(&b);
 266         if(rlen != 0)
 267                 error("do_convert_private_ssh2_from_blob: "
 268                     "remaining bytes in key blob %d", rlen);
 269         buffer_free(&b);
 270
 271         /* try the key */
 272         key_sign(key, &sig, &slen, data, sizeof(data));
 273         key_verify(key, sig, slen, data, sizeof(data));
 274         xfree(sig);
 275         return key;
 276 }
 277
 278 static void
 279 do_convert_from_ssh2(struct passwd *pw)
 280 {
 281         Key *k;
 282         int blen;
 283         char line[1024], *p;
 284         char blob[8096];
 285         char encoded[8096];
 286         struct stat st;
 287         int escaped = 0, private = 0, ok;
 288         FILE *fp;
 289
 290         if (!have_identity)
 291                 ask_filename(pw, "Enter file in which the key is");
 292         if (stat(identity_file, &st) < 0) {
 293                 perror(identity_file);
 294                 exit(1);
 295         }
 296         fp = fopen(identity_file, "r");
 297         if (fp == NULL) {
 298                 perror(identity_file);
 299                 exit(1);
 300         }
 301         encoded[0] = '\0';
 302         while (fgets(line, sizeof(line), fp)) {
 303                 if (!(p = strchr(line, '\n'))) {
 304                         fprintf(stderr, "input line too long.\n");
 305                         exit(1);
 306                 }
 307                 if (p > line && p[-1] == '\\')
 308                         escaped++;
 309                 if (strncmp(line, "----", 4) == 0 ||
 310                     strstr(line, ": ") != NULL) {
 311                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
 312                                 private = 1;
 313                         if (strstr(line, " END ") != NULL) {
 314                                 break;
 315                         }
 316                         /* fprintf(stderr, "ignore: %s", line); */
 317                         continue;
 318                 }
 319                 if (escaped) {
 320                         escaped--;
 321                         /* fprintf(stderr, "escaped: %s", line); */
 322                         continue;
 323                 }
 324                 *p = '\0';
 325                 strlcat(encoded, line, sizeof(encoded));
 326         }
 327         blen = uudecode(encoded, (u_char *)blob, sizeof(blob));
 328         if (blen < 0) {
 329                 fprintf(stderr, "uudecode failed.\n");
 330                 exit(1);
 331         }
 332         k = private ?
 333             do_convert_private_ssh2_from_blob(blob, blen) :
 334             key_from_blob(blob, blen);
 335         if (k == NULL) {
 336                 fprintf(stderr, "decode blob failed.\n");
 337                 exit(1);
 338         }
 339         ok = private ?
 340             (k->type == KEY_DSA ?
 341                  PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
 342                  PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
 343             key_write(k, stdout);
 344         if (!ok) {
 345                 fprintf(stderr, "key write failed");
 346                 exit(1);
 347         }
 348         key_free(k);
 349         fprintf(stdout, "\n");
 350         fclose(fp);
 351         exit(0);
 352 }
 353
 354 static void
 355 do_print_public(struct passwd *pw)
 356 {
 357         Key *prv;
 358         struct stat st;
 359
 360         if (!have_identity)
 361                 ask_filename(pw, "Enter file in which the key is");
 362         if (stat(identity_file, &st) < 0) {
 363                 perror(identity_file);
 364                 exit(1);
 365         }
 366         prv = load_identity(identity_file);
 367         if (prv == NULL) {
 368                 fprintf(stderr, "load failed\n");
 369                 exit(1);
 370         }
 371         if (!key_write(prv, stdout))
 372                 fprintf(stderr, "key_write failed");
 373         key_free(prv);
 374         fprintf(stdout, "\n");
 375         exit(0);
 376 }
 377
 378 static void
 379 do_fingerprint(struct passwd *pw)
 380 {
 381         FILE *f;
 382         Key *public;
 383         char *comment = NULL, *cp, *ep, line[16*1024], *fp;
 384         int i, skip = 0, num = 1, invalid = 1, rep, fptype;
 385         struct stat st;
 386
 387         fptype = print_bubblebabble ? SSH_FP_SHA1 : SSH_FP_MD5;
 388         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_HEX;
 389
 390         if (!have_identity)
 391                 ask_filename(pw, "Enter file in which the key is");
 392         if (stat(identity_file, &st) < 0) {
 393                 perror(identity_file);
 394                 exit(1);
 395         }
 396         public = key_load_public(identity_file, &comment);
 397         if (public != NULL) {
 398                 fp = key_fingerprint(public, fptype, rep);
 399                 printf("%d %s %s\n", key_size(public), fp, comment);
 400                 key_free(public);
 401                 xfree(comment);
 402                 xfree(fp);
 403                 exit(0);
 404         }
 405         if (comment)
 406                 xfree(comment);
 407
 408         f = fopen(identity_file, "r");
 409         if (f != NULL) {
 410                 while (fgets(line, sizeof(line), f)) {
 411                         i = strlen(line) - 1;
 412                         if (line[i] != '\n') {
 413                                 error("line %d too long: %.40s...", num, line);
 414                                 skip = 1;
 415                                 continue;
 416                         }
 417                         num++;
 418                         if (skip) {
 419                                 skip = 0;
 420                                 continue;
 421                         }
 422                         line[i] = '\0';
 423
 424                         /* Skip leading whitespace, empty and comment lines. */
 425                         for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
 426                                 ;
 427                         if (!*cp || *cp == '\n' || *cp == '#')
 428                                 continue ;
 429                         i = strtol(cp, &ep, 10);
 430                         if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
 431                                 int quoted = 0;
 432                                 comment = cp;
 433                                 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
 434                                         if (*cp == '\\' && cp[1] == '"')
 435                                                 cp++;   /* Skip both */
 436                                         else if (*cp == '"')
 437                                                 quoted = !quoted;
 438                                 }
 439                                 if (!*cp)
 440                                         continue;
 441                                 *cp++ = '\0';
 442                         }
 443                         ep = cp;
 444                         public = key_new(KEY_RSA1);
 445                         if (key_read(public, &cp) != 1) {
 446                                 cp = ep;
 447                                 key_free(public);
 448                                 public = key_new(KEY_UNSPEC);
 449                                 if (key_read(public, &cp) != 1) {
 450                                         key_free(public);
 451                                         continue;
 452                                 }
 453                         }
 454                         comment = *cp ? cp : comment;
 455                         fp = key_fingerprint(public, fptype, rep);
 456                         printf("%d %s %s\n", key_size(public), fp,
 457                             comment ? comment : "no comment");
 458                         xfree(fp);
 459                         key_free(public);
 460                         invalid = 0;
 461                 }
 462                 fclose(f);
 463         }
 464         if (invalid) {
 465                 printf("%s is not a valid key file.\n", identity_file);
 466                 exit(1);
 467         }
 468         exit(0);
 469 }
 470
 471 /*
 472  * Perform changing a passphrase.  The argument is the passwd structure
 473  * for the current user.
 474  */
 475 static void
 476 do_change_passphrase(struct passwd *pw)
 477 {
 478         char *comment;
 479         char *old_passphrase, *passphrase1, *passphrase2;
 480         struct stat st;
 481         Key *private;
 482
 483         if (!have_identity)
 484                 ask_filename(pw, "Enter file in which the key is");
 485         if (stat(identity_file, &st) < 0) {
 486                 perror(identity_file);
 487                 exit(1);
 488         }
 489         /* Try to load the file with empty passphrase. */
 490         private = key_load_private(identity_file, "", &comment);
 491         if (private == NULL) {
 492                 if (identity_passphrase)
 493                         old_passphrase = xstrdup(identity_passphrase);
 494                 else
 495                         old_passphrase =
 496                             read_passphrase("Enter old passphrase: ",
 497                             RP_ALLOW_STDIN);
 498                 private = key_load_private(identity_file, old_passphrase,
 499                     &comment);
 500                 memset(old_passphrase, 0, strlen(old_passphrase));
 501                 xfree(old_passphrase);
 502                 if (private == NULL) {
 503                         printf("Bad passphrase.\n");
 504                         exit(1);
 505                 }
 506         }
 507         printf("Key has comment '%s'\n", comment);
 508
 509         /* Ask the new passphrase (twice). */
 510         if (identity_new_passphrase) {
 511                 passphrase1 = xstrdup(identity_new_passphrase);
 512                 passphrase2 = NULL;
 513         } else {
 514                 passphrase1 =
 515                         read_passphrase("Enter new passphrase (empty for no "
 516                             "passphrase): ", RP_ALLOW_STDIN);
 517                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 518                      RP_ALLOW_STDIN);
 519
 520                 /* Verify that they are the same. */
 521                 if (strcmp(passphrase1, passphrase2) != 0) {
 522                         memset(passphrase1, 0, strlen(passphrase1));
 523                         memset(passphrase2, 0, strlen(passphrase2));
 524                         xfree(passphrase1);
 525                         xfree(passphrase2);
 526                         printf("Pass phrases do not match.  Try again.\n");
 527                         exit(1);
 528                 }
 529                 /* Destroy the other copy. */
 530                 memset(passphrase2, 0, strlen(passphrase2));
 531                 xfree(passphrase2);
 532         }
 533
 534         /* Save the file using the new passphrase. */
 535         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 536                 printf("Saving the key failed: %s.\n", identity_file);
 537                 memset(passphrase1, 0, strlen(passphrase1));
 538                 xfree(passphrase1);
 539                 key_free(private);
 540                 xfree(comment);
 541                 exit(1);
 542         }
 543         /* Destroy the passphrase and the copy of the key in memory. */
 544         memset(passphrase1, 0, strlen(passphrase1));
 545         xfree(passphrase1);
 546         key_free(private);               /* Destroys contents */
 547         xfree(comment);
 548
 549         printf("Your identification has been saved with the new passphrase.\n");
 550         exit(0);
 551 }
 552
 553 /*
 554  * Change the comment of a private key file.
 555  */
 556 static void
 557 do_change_comment(struct passwd *pw)
 558 {
 559         char new_comment[1024], *comment, *passphrase;
 560         Key *private;
 561         Key *public;
 562         struct stat st;
 563         FILE *f;
 564         int fd;
 565
 566         if (!have_identity)
 567                 ask_filename(pw, "Enter file in which the key is");
 568         if (stat(identity_file, &st) < 0) {
 569                 perror(identity_file);
 570                 exit(1);
 571         }
 572         private = key_load_private(identity_file, "", &comment);
 573         if (private == NULL) {
 574                 if (identity_passphrase)
 575                         passphrase = xstrdup(identity_passphrase);
 576                 else if (identity_new_passphrase)
 577                         passphrase = xstrdup(identity_new_passphrase);
 578                 else
 579                         passphrase = read_passphrase("Enter passphrase: ",
 580                             RP_ALLOW_STDIN);
 581                 /* Try to load using the passphrase. */
 582                 private = key_load_private(identity_file, passphrase, &comment);
 583                 if (private == NULL) {
 584                         memset(passphrase, 0, strlen(passphrase));
 585                         xfree(passphrase);
 586                         printf("Bad passphrase.\n");
 587                         exit(1);
 588                 }
 589         } else {
 590                 passphrase = xstrdup("");
 591         }
 592         if (private->type != KEY_RSA1) {
 593                 fprintf(stderr, "Comments are only supported for RSA1 keys.\n");
 594                 key_free(private);
 595                 exit(1);
 596         }
 597         printf("Key now has comment '%s'\n", comment);
 598
 599         if (identity_comment) {
 600                 strlcpy(new_comment, identity_comment, sizeof(new_comment));
 601         } else {
 602                 printf("Enter new comment: ");
 603                 fflush(stdout);
 604                 if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 605                         memset(passphrase, 0, strlen(passphrase));
 606                         key_free(private);
 607                         exit(1);
 608                 }
 609                 if (strchr(new_comment, '\n'))
 610                         *strchr(new_comment, '\n') = 0;
 611         }
 612
 613         /* Save the file using the new passphrase. */
 614         if (!key_save_private(private, identity_file, passphrase, new_comment)) {
 615                 printf("Saving the key failed: %s.\n", identity_file);
 616                 memset(passphrase, 0, strlen(passphrase));
 617                 xfree(passphrase);
 618                 key_free(private);
 619                 xfree(comment);
 620                 exit(1);
 621         }
 622         memset(passphrase, 0, strlen(passphrase));
 623         xfree(passphrase);
 624         public = key_from_private(private);
 625         key_free(private);
 626
 627         strlcat(identity_file, ".pub", sizeof(identity_file));
 628         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 629         if (fd == -1) {
 630                 printf("Could not save your public key in %s\n", identity_file);
 631                 exit(1);
 632         }
 633         f = fdopen(fd, "w");
 634         if (f == NULL) {
 635                 printf("fdopen %s failed", identity_file);
 636                 exit(1);
 637         }
 638         if (!key_write(public, f))
 639                 fprintf(stderr, "write key failed");
 640         key_free(public);
 641         fprintf(f, " %s\n", new_comment);
 642         fclose(f);
 643
 644         xfree(comment);
 645
 646         printf("The comment in your key file has been changed.\n");
 647         exit(0);
 648 }
 649
 650 static void
 651 usage(void)
 652 {
 653         printf("Usage: %s [-ceilpqyB] [-t type] [-b bits] [-f file] [-C comment] "
 654             "[-N new-pass] [-P pass]\n", __progname);
 655         exit(1);
 656 }
 657
 658 /*
 659  * Main program for key management.
 660  */
 661 int
 662 main(int ac, char **av)
 663 {
 664         char dotsshdir[16 * 1024], comment[1024], *passphrase1, *passphrase2;
 665         Key *private, *public;
 666         struct passwd *pw;
 667         int opt, type, fd;
 668         struct stat st;
 669         FILE *f;
 670
 671         extern int optind;
 672         extern char *optarg;
 673
 674         __progname = get_progname(av[0]);
 675         init_rng();
 676         seed_rng();
 677
 678         SSLeay_add_all_algorithms();
 679
 680         /* we need this for the home * directory.  */
 681         pw = getpwuid(getuid());
 682         if (!pw) {
 683                 printf("You don't exist, go away!\n");
 684                 exit(1);
 685         }
 686         if (gethostname(hostname, sizeof(hostname)) < 0) {
 687                 perror("gethostname");
 688                 exit(1);
 689         }
 690
 691         while ((opt = getopt(ac, av, "deiqpclBRxXyb:f:t:P:N:C:")) != -1) {
 692                 switch (opt) {
 693                 case 'b':
 694                         bits = atoi(optarg);
 695                         if (bits < 512 || bits > 32768) {
 696                                 printf("Bits has bad value.\n");
 697                                 exit(1);
 698                         }
 699                         break;
 700
 701                 case 'l':
 702                         print_fingerprint = 1;
 703                         break;
 704
 705                 case 'B':
 706                         print_bubblebabble = 1;
 707                         break;
 708
 709                 case 'p':
 710                         change_passphrase = 1;
 711                         break;
 712
 713                 case 'c':
 714                         change_comment = 1;
 715                         break;
 716
 717                 case 'f':
 718                         strlcpy(identity_file, optarg, sizeof(identity_file));
 719                         have_identity = 1;
 720                         break;
 721
 722                 case 'P':
 723                         identity_passphrase = optarg;
 724                         break;
 725
 726                 case 'N':
 727                         identity_new_passphrase = optarg;
 728                         break;
 729
 730                 case 'C':
 731                         identity_comment = optarg;
 732                         break;
 733
 734                 case 'q':
 735                         quiet = 1;
 736                         break;
 737
 738                 case 'R':
 739                         /* unused */
 740                         exit(0);
 741                         break;
 742
 743                 case 'e':
 744                 case 'x':
 745                         /* export key */
 746                         convert_to_ssh2 = 1;
 747                         break;
 748
 749                 case 'i':
 750                 case 'X':
 751                         /* import key */
 752                         convert_from_ssh2 = 1;
 753                         break;
 754
 755                 case 'y':
 756                         print_public = 1;
 757                         break;
 758
 759                 case 'd':
 760                         key_type_name = "dsa";
 761                         break;
 762
 763                 case 't':
 764                         key_type_name = optarg;
 765                         break;
 766
 767                 case '?':
 768                 default:
 769                         usage();
 770                 }
 771         }
 772         if (optind < ac) {
 773                 printf("Too many arguments.\n");
 774                 usage();
 775         }
 776         if (change_passphrase && change_comment) {
 777                 printf("Can only have one of -p and -c.\n");
 778                 usage();
 779         }
 780         if (print_fingerprint || print_bubblebabble)
 781                 do_fingerprint(pw);
 782         if (change_passphrase)
 783                 do_change_passphrase(pw);
 784         if (change_comment)
 785                 do_change_comment(pw);
 786         if (convert_to_ssh2)
 787                 do_convert_to_ssh2(pw);
 788         if (convert_from_ssh2)
 789                 do_convert_from_ssh2(pw);
 790         if (print_public)
 791                 do_print_public(pw);
 792
 793         arc4random_stir();
 794
 795         type = key_type_from_name(key_type_name);
 796         if (type == KEY_UNSPEC) {
 797                 fprintf(stderr, "unknown key type %s\n", key_type_name);
 798                 exit(1);
 799         }
 800         if (!quiet)
 801                 printf("Generating public/private %s key pair.\n", key_type_name);
 802         private = key_generate(type, bits);
 803         if (private == NULL) {
 804                 fprintf(stderr, "key_generate failed");
 805                 exit(1);
 806         }
 807         public  = key_from_private(private);
 808
 809         if (!have_identity)
 810                 ask_filename(pw, "Enter file in which to save the key");
 811
 812         /* Create ~/.ssh directory if it doesn\'t already exist. */
 813         snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
 814         if (strstr(identity_file, dotsshdir) != NULL &&
 815             stat(dotsshdir, &st) < 0) {
 816                 if (mkdir(dotsshdir, 0700) < 0)
 817                         error("Could not create directory '%s'.", dotsshdir);
 818                 else if (!quiet)
 819                         printf("Created directory '%s'.\n", dotsshdir);
 820         }
 821         /* If the file already exists, ask the user to confirm. */
 822         if (stat(identity_file, &st) >= 0) {
 823                 char yesno[3];
 824                 printf("%s already exists.\n", identity_file);
 825                 printf("Overwrite (y/n)? ");
 826                 fflush(stdout);
 827                 if (fgets(yesno, sizeof(yesno), stdin) == NULL)
 828                         exit(1);
 829                 if (yesno[0] != 'y' && yesno[0] != 'Y')
 830                         exit(1);
 831         }
 832         /* Ask for a passphrase (twice). */
 833         if (identity_passphrase)
 834                 passphrase1 = xstrdup(identity_passphrase);
 835         else if (identity_new_passphrase)
 836                 passphrase1 = xstrdup(identity_new_passphrase);
 837         else {
 838 passphrase_again:
 839                 passphrase1 =
 840                         read_passphrase("Enter passphrase (empty for no "
 841                             "passphrase): ", RP_ALLOW_STDIN);
 842                 passphrase2 = read_passphrase("Enter same passphrase again: ",
 843                     RP_ALLOW_STDIN);
 844                 if (strcmp(passphrase1, passphrase2) != 0) {
 845                         /*
 846                          * The passphrases do not match.  Clear them and
 847                          * retry.
 848                          */
 849                         memset(passphrase1, 0, strlen(passphrase1));
 850                         memset(passphrase2, 0, strlen(passphrase2));
 851                         xfree(passphrase1);
 852                         xfree(passphrase2);
 853                         printf("Passphrases do not match.  Try again.\n");
 854                         goto passphrase_again;
 855                 }
 856                 /* Clear the other copy of the passphrase. */
 857                 memset(passphrase2, 0, strlen(passphrase2));
 858                 xfree(passphrase2);
 859         }
 860
 861         if (identity_comment) {
 862                 strlcpy(comment, identity_comment, sizeof(comment));
 863         } else {
 864                 /* Create default commend field for the passphrase. */
 865                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
 866         }
 867
 868         /* Save the key with the given passphrase and comment. */
 869         if (!key_save_private(private, identity_file, passphrase1, comment)) {
 870                 printf("Saving the key failed: %s.\n", identity_file);
 871                 memset(passphrase1, 0, strlen(passphrase1));
 872                 xfree(passphrase1);
 873                 exit(1);
 874         }
 875         /* Clear the passphrase. */
 876         memset(passphrase1, 0, strlen(passphrase1));
 877         xfree(passphrase1);
 878
 879         /* Clear the private key and the random number generator. */
 880         key_free(private);
 881         arc4random_stir();
 882
 883         if (!quiet)
 884                 printf("Your identification has been saved in %s.\n", identity_file);
 885
 886         strlcat(identity_file, ".pub", sizeof(identity_file));
 887         fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 888         if (fd == -1) {
 889                 printf("Could not save your public key in %s\n", identity_file);
 890                 exit(1);
 891         }
 892         f = fdopen(fd, "w");
 893         if (f == NULL) {
 894                 printf("fdopen %s failed", identity_file);
 895                 exit(1);
 896         }
 897         if (!key_write(public, f))
 898                 fprintf(stderr, "write key failed");
 899         fprintf(f, " %s\n", comment);
 900         fclose(f);
 901
 902         if (!quiet) {
 903                 char *fp = key_fingerprint(public, SSH_FP_MD5, SSH_FP_HEX);
 904                 printf("Your public key has been saved in %s.\n",
 905                     identity_file);
 906                 printf("The key fingerprint is:\n");
 907                 printf("%s %s\n", fp, comment);
 908                 xfree(fp);
 909         }
 910
 911         key_free(public);
 912         exit(0);
 913 }